Robberies both traumatize victims and unsettle residents of the neighborhood in which they occur. When individuals do not feel safe and an area becomes associated with street crime, people are less likely to reside in, travel to or conduct business there. As a result, such neighborhoods can become economically depressed and suffer from persistent levels of crime. Studies have even shown collective psychological effects in such neighborhoods.

It should be noted, however, that the number of robberies in the United States has been cut roughly in half over the past 20 years — from 687,732 in 1991 to 367,832 in 2010, according to FBI data. Over that period, the rate of robberies has also fallen dramatically, from 273 robberies per 100,000 persons in 1991 to 119 per 100,000 in 2010.

A 2012 study from Loyola University of Chicago and the Netherlands Institute for the Study of Crime and Law Enforcement, “Go Where the Money Is: Modeling Street Robbers’ Location Choices,” examines how thieves decide on the location in which to act. The study, published in the Journal of Economic Geography, analyzed data from the Chicago Police Department relating to 12,938 robberies, which occurred on 24,594 census blocks in Chicago between 1996 to 1998. These crimes involved nearly 18,000 perpetrators. The study provides unique insights primarily by studying crime through an economic lens.

Key findings include:

• A robbery was more likely to occur when the location is close to the robber’s home. For “each log-kilometer” a block was to a robber’s home, it was “5.32 times more likely to get selected for robbery.”
• The existence of certain kinds of businesses on a given block was associated with a higher likelihood of being selected for robbery: bars, clubs, fast food restaurants, hair salons and barbershops, liquor stores, groceries, gas stations, laundromats, pawn shops, and check cashing places. This is likely because these places conduct a substantial amount of transactions in cash.
• Areas in which other vice activities such as “drugs, prostitution and gambling” were prevalent were much more likely to be selected for robbery than areas in which they were absent.
• Blocks that were close to a train station were 3.43 times more likely to be selected for a robbery than those without train stations.
• The existence of a high school on a block resulted in a 1.78 times greater likelihood of a robbery taking place on the block, compared with those without high schools. However, although high schools may have a high population of potential victims, “the students attending the school may also be offenders for whom the school and the nearby area represent an anchor point that they are familiar with.”
• The race of the robber had a strong effect on what areas they decided to target. African-American robbers were 1.98 times more likely to target a majority African-American block; Hispanic robbers were 3.82 times more likely to target a majority Hispanic block; and Caucasian robbers were more likely to target a predominantly white block.
• In most of the cases examined, blocks near locations typically selected for robbery were also more likely to be selected for such crimes. There is a “spillover,” in other words, to adjacent blocks, and robbers act near the locations “that their potential victims are heading to or returning from.”

Overall, the authors found that robbers “were most likely to attack on easily accessible blocks, where legal and illegal cash economies are present.” Furthermore they suggested that possible deterrents for street robbers “include law enforcement activity… victim vigilance… and criminal competition,” but an examination of deterrents of criminals was outside the scope of their study and should be further examined in future literature on this topic. In sum, the researchers demonstrated that blocks become less attractive for committing robbery, the larger the physical distance to the street robber’s residence and the larger the social distance to the street robber’s racial/ethnic background: “For example, Chicago street robbers prefer blocks nearby their homes and blocks that have majority populations matching their own racial or ethnic background.”

Related research: related 2012 study from Michigan State University, “Using Public Health Methods to Investigate the Diffusion of Homicide,” examines how homicide “spreads” spatially in a city and provides insights on the geography of violent crime. For more on the changing dynamics of many traditionally high-crime urban areas in the United States, see this research review.

Keywords: crime, policing, guns